One method of manufacturing plastic/acrylic signs, bath tubs, sinks, spas, marine parts and the like includes forming a thermoplastic substrate with a high surface finish or other types of substrates and attaching a secondary layer(s) by spraying a mixture of fiberglass and polyester resin thereon. The sprayed-on material can then be subjected to patting and rolling to smooth down the entrapped fiberglass and remove any air pockets. The substrate can then be allowed to cure at ambient temperature to achieve a coated fiberglass and polyester resin reinforced substrate. Another method includes a process for applying a polyurethane coating formed from simultaneously mixing and spray applying at least two polyurethane components to a thermoformed substrate which is nearly 100% reactive and releases little or no styrene. This process generates sufficient adhesion to the thermoformed part and the required strength for its intended use.
The above methods and systems employing this and similar methods are typically manually operated or require skilled labor. However, any problems with manual operation or skilled labor, such as training or incorrect application of one or more mixtures can lead to manufacturing defects in the finished product. For example, if a suitable substrate temperature is not achieved prior to applying a polyurethane coating to the substrate, the polyurethane coating may not properly adhere to the substrate. In yet another example, if during the coating process the substrate temperature is too high, the substrate may soften and distort in shape. In another example, in a multi-component polyurethane coating for a substrate, if the components are not properly mixed, poor adhesion and/or delamination of the coating can occur causing blisters or bubbles which may not be manifested or observed until several months after the coating is applied. Yet another example involves the negative effect of moisture on the surface of the substrate to be coated with the polyurethane. The relative humidity, ambient temperature, or dew point during the application of polyurethane coating components can adversely affect the coating properties, causing blistering or bubbling in the material, thus possibly leading to defects during manufacturing or several months afterwards. Manufacturing defects are not normally detected during the manufacturing phase, thus numerous products may be made, packaged, and shipped to customers long before a defect can be detected. Once a manufacturing defect is detected, the finished product is likely to be in use by a customer or on the shelf of a retailer or distributor, thus recalling the defective product can be difficult, expensive, and time consuming.
Therefore a need exists for systems and methods for monitoring and controlling operating characteristics used in a process for manufacturing production parts. Another need exists for systems and methods for alerting personnel to deviations outside preferred operating characteristics used in a manufacturing process. Yet another need exists for systems and methods for recording operating characteristics used during manufacturing. Another need exists for systems and methods for monitoring and controlling laminate thickness for articles of manufacture. Still another need exists for systems and methods for providing electronic quality control for applying a polyurethane coating to a substrate. Yet another need exists for systems and methods for providing electronic quality control for manufacturing a polyurethane coated article.